The present invention relates to a method of loosely prefixing at least two components that are to be firmly connected with one another, especially two body parts of a vehicle body that are to be firmly connected with one another.
Such a method is known from an earlier German Patent Application DE 10 2008 038 747.9, which is not a prior publication.
In the large-series production of vehicle bodies, a plurality of individual body parts are assembled in a largely fully automatic manner. During a joining operation, two or more vehicle body parts are first positioned relative to one another by means of a high-expenditure chucking and receiving technique and are subsequently connected with one another, for example, by welding, clinching or other joining methods.
In order to ensure a high dimensional accuracy of the vehicle body, it is important that the vehicle body parts to be joined are positioned as precisely as possible relative to one another before the connection. In the case of conventional manufacturing systems, a vehicle body part to be joined is first precisely positioned with respect to the system or with respect to another component by use of mechanical chucking devices. The components to be joined will then be joined, for example, by being welded to one another. This method of positioning vehicle body parts to be joined can be called a “standard method” because it has been successful for many years. The dimensional accuracy of the vehicle body, on the one hand, depends on a positioning of the vehicle body parts to be joined that is as accurate as possible with respect to the “system” and, on the other hand, on how precisely the “system” (for example, the chucking device) brings the vehicle body part, that is to be joined and is positioned on it, into the joining position.
It is an object of the invention to provide a method of loosely prefixing at least two components to be firmly connected with one another, which method is easy to implement and, in a simple fashion, permits an exact alignment of the loosely prefixed components with a view to a subsequent joining operation.
This and other objects are achieved by a method of fixing, particularly of loosely prefixing, at least two components to be firmly connected with one another, particularly two body parts of a vehicle body to be firmly connected with one another or of fixing an add-on component or an (interior) fitting to a vehicle body component. The components consist of a first component on which at least one first form-locking element is provided, which projects from the first component, and of a second component which has a second form-locking element interacting with the first form-locking element of the first component.
By placing the two components together such that the form-locking elements interlock with one another and, as a result, hold the two components relative to one another at least in one direction, the two components are fixed or loosely prefixed.
In this context, the word “prefixing” means that the components are not permanently firmly connected with one another but can be separated from one another again without any problem. It may be provided that, by way of the mutually interlocking form-locking elements, the two components are fixed on the form-locking elements in a firm manner or with a certain amount of play in one, two or more directions in space relative to one another. In particular, it may be provided that, as a result of the two form-locking elements, the two components are displaceable relative to one another in one direction and, in the remaining directions in space, are firmly or almost firmly, with the exception of a predefined play, coupled to one another.
At least one first form-locking element is a separate part that differs from the first component and that is connected with the first component during or after the manufacturing of the first component.
In order to facilitate the mutual placing together and interlocking of the form-locking elements and to permit a moving of the form-locking elements relative to one another that is free of tilting, it is advantageous for the first form-locking element to be completely or partly rotationally symmetrical with respect to the normal surface line of the first component at the fastening point of the first form-locking element. Basically, for example, circular-cylindrical, truncated-cone-shaped or conical geometries are considered for the first form-locking element.
However, preferably first form-locking elements may be considered which completely or partly have the shape of a sphere or which completely or partly have a shape similar to a sphere. Similar to a sphere may mean, for example, that the shape is convexly curved, preferably rotationally symmetrically with respect to the direction of a normal line. Such “round or curved or convex geometries” simplify the “placing in one another” of the form-locking elements. A tilting of the form-locking elements is largely avoided by such a geometry when the two components are aligned relative one another.
According to a further aspect of the invention, the first form-locking element is designed such that it “tapers” at least in an area in the direction toward the first component, whereby an “undercut” is produced when the two components are placed together. This is particularly true in the case of a spherical form-locking element that is connected with the first component.
The first form-locking element can, for example, be screwed, riveted, glued or otherwise connected with the first component. Particularly a material-locking connection of the first form-locking element with the first component is also contemplated. The first form-locking element and the first component may each consist of metal. In this case, the first form-locking element can simply be welded onto the first component.
According to a further aspect of the invention, the second form-locking element is formed by a recess provided in the second component. This recess may have a slot-shaped design. Correspondingly, it may be provided that, in the loosely prefixed position of the two components, the first form-locking element reaches in a form-locking manner behind at least one area of the second form-locking element and, in a longitudinal direction of the second form-locking element or of the recess can be displaced relative thereto.
According to a still further aspect of the invention, the recess forming the second form-locking element is designed such that it has a first area that is dimensioned in such a manner that the first form-locking element can be fitted through it, and a second area directly adjoining the first area, which second area is narrower, so that the first form-locking element can be pushed into this area but cannot be pulled out perpendicularly thereto.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.